Fuel pump wiring diagram

Tiny
TLGARRISON
  • 1999 DODGE RAM

V8 two wheel drive automatic 167000 miles.

I recently have had random shutdowns while driving my truck. Driving along at fifty five mph and all the sudden a loss of power. Pull over to the side. I turned key off then on again and it started.

A few blocks down the road it did it again very quickly though. It lost power (like not getting fuel) slowed down and then it came back and I continued on to the gas station. I thought fuel problem (3/4 of tank of gas) so I got some STP gas treatment at the station.

No problems for a couple of days and then all of the sudden it did it again. This time it would not come back on. I was thinking fuel pump. But I noticed something strange. When I would turn the key to the "on" position all the gauges (gas gauge/oil gauge/battery gauge) would move a little but go back to the flat position. This made me think it was some sort of electrical or relay problem. I opened the hood and found the relay box and just gently tapped on the top of the relays etc.

I got back in the car and when I turned the key to the "on" position all my gauges were working (coincidence? ). The truck started and worked fine.

Is there something other than a relay that can cause this kind of symptom. If the relay is bad would it cause the fuel gauge to not respond?

Checked the relays, and under the box I do not see any corrosion or anything that is loose.

When problem happened last time:

1) Lost power (like out of gas).

2) would not start but starter would crank.

3) Gauges, fuel gauge would not register fuel but power was going to the gauges. When I turned the ignition to on the fuel gauge would rise eighth of an inch but then drop back down. After messing with relays etc (about five minutes). I turned Ignition to on and the gauge worked and then the truck would start.

That was yesterday and it has not happened since.

After reading your message, I am wondering if it is electrical. Is there something under the dash or in the steering column that if it were to short would cause the symptoms I have described?

If the fuel pump is bad will you still have fuel reading on the dashboard gauge? Or is that controlled by a different mechanism?

I tried cleaning connectors, swapped relays.

Drove fine since July 7th.

It happened again today July 13th. This time it provided me with another clue. I notice where the odometer readout is, the words "no bus".

I opened the hood and messed with relays and nothing happened. I turned key off then on again and odometer was normal but fuel gauge did not read anything. I plugged in my code reader and waited and then the odometer read "no bus" again.

I figure that it is the PCM or the connections to it. So I took my screwdriver and lightly tapped a small black box that is located behind the Relay box (Is that the PCM?)

I got in and turned the key to on and the fuel gauge went up. Truck started.

Is there something I can do to check the connections and rule out that the PCM (computer) is bad?

Anything else I should check given this new clue?

Thanks

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Thursday, July 8th, 2010 AT 9:22 AM

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Tiny
JACOBANDNICKOLAS
  • EXPERT
  • 68,278 POSTS

That is a good clue. The no bus indicates there is no communication between the PCM and its components. Just remove the wiring harness to it and check for corrosion and make sure everything is tight.

Let me know what you find.

Joe
PS: I believe what you described is the PCM and usually they are either good or bad, so my guess is a bad connection or broken wire.

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Friday, July 16th, 2010 AT 11:03 PM
Tiny
TLGARRISON
  • MEMBER

Found the problem! It was the "engine inline" plug that plugs into the black fuse box under the hood that houses the relays etc. See picture (top left hand corner of box).

I unscrewed the screw (noticed it was a little loose). cleaned contacts on the pins with contact cleaner and then applied dialectric grease to the contacts; screwed it back in place and it has been running like a top ever since. This is one for the books!!!

Thanks for all the help. This is a great site!


http://www.2carpros.com/forum/automotive_pictures/547721_EngineInline_1.jpg

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Thursday, July 22nd, 2010 AT 5:39 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
  • 68,278 POSTS

Great job. That is what was causing the no bus signal. Thanks for using 2carpros. Com, and let us know if you have questions in the future.

Joe

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Thursday, July 22nd, 2010 AT 11:48 PM
Tiny
EHRICHWEISS
  • MEMBER

I am sorry but the ASD does not stop the starter from cranking the engine. That is not remotely factual there. My PCM is giving me code 12(ASD relay issues) and my starter definitely cranks. The ASD has nothing to do with the starter, nor should it.

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Friday, January 20th, 2017 AT 4:08 PM
Tiny
CARADIODOC
  • EXPERT
  • 28,379 POSTS

Code 12 just means power was lost to the engine computer recently, typically because the battery was disconnected. This applies to 1995 and older models.

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Friday, January 20th, 2017 AT 9:18 PM
Tiny
EHRICHWEISS
  • MEMBER

You are right, I apparently wrote the last code I had researched. 42 was the one I should have written. I do have a code 12 but I am unsure if it has been 50 power cycles since I pulled the battery. Anyway, my starter will definitely turn over, even with the ASD relay removed.

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Friday, January 20th, 2017 AT 10:52 PM
Tiny
CARADIODOC
  • EXPERT
  • 28,379 POSTS

Yup. Are you trying to solve a problem or just adding information to the previous post?

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Saturday, January 21st, 2017 AT 3:11 PM
Tiny
EHRICHWEISS
  • MEMBER

Was just adding information so that someone did not think that was a definite thing to consider when diagnosing the ASD.

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Saturday, January 21st, 2017 AT 3:29 PM
Tiny
CARADIODOC
  • EXPERT
  • 28,379 POSTS

Dandy. Carry on!

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Saturday, January 21st, 2017 AT 3:38 PM
Tiny
2CARPROS KEN
  • ADMIN
  • 8,530 POSTS

Hello,

I found the fuel pump and engine wiring diagrams for you (below) just in case someone needs it.

Please let us know what happens.

Cheers, Ken

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Monday, May 29th, 2017 AT 9:06 PM
Tiny
AUSTIN MCCLANAHAN
  • 2001 DODGE RAM
  • 5.9L
  • V8
  • 4WD
  • AUTOMATIC
  • 137,000 MILES

Truck will start only if I put start fluid in throttle body and then it will not run right and is weak. The voltage indicator on cluster is all the way down and the mil is showing something to do with the ASD Relay. Please help!

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Monday, May 29th, 2017 AT 9:07 PM (Merged)
Tiny
HMAC300
  • EXPERT
  • 49,624 POSTS

Scan for codes and check fuel pressure with a gauge auto parts rent it. See link. We need the code to further help you.
https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

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Monday, May 29th, 2017 AT 9:07 PM (Merged)
Tiny
AUSTIN MCCLANAHAN
  • MEMBER

I have not checked with a gauge yet, but I opened the "S" valve with a pen and when the fuel pump engaged it shot out and had great pressure. I also checked plugs and I am getting a spark at the plug.

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Monday, May 29th, 2017 AT 9:07 PM (Merged)
Tiny
HMAC300
  • EXPERT
  • 49,624 POSTS

Check it with a gauge finger style is no good. What is code given?

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Monday, May 29th, 2017 AT 9:07 PM (Merged)
Tiny
AUSTIN MCCLANAHAN
  • MEMBER

I found out the problem. The number 12 pin going from the harness to the PCM has burnt.

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Monday, May 29th, 2017 AT 9:07 PM (Merged)
Tiny
2CARPROS KEN
  • ADMIN
  • 8,530 POSTS

That will do it, this is probably related to the shorted alternator or fuel injector.

Please let us know happens so it will help others.

Best, Ken

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Monday, May 29th, 2017 AT 9:07 PM (Merged)
Tiny
AUSTIN MCCLANAHAN
  • MEMBER

Alternator sounded horrible so I took it off and took it to have it tested and it passed, but had a low voltage output and had something inside of it jumping around (I replaced it). I also found that my ignition coil wire had got it self beside the manifold and had started shorting out (replaced as well). What do you think could have been the cause for this? I do not want to spend $200.00 for the same thing to happen.

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Monday, May 29th, 2017 AT 9:07 PM (Merged)
Tiny
HMAC300
  • EXPERT
  • 49,624 POSTS

Mileage and age for one thing and alternator went bad. If you want you can put electrical conduit around plug wires to help from shorting out it is available at auto parts.

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Monday, May 29th, 2017 AT 9:07 PM (Merged)
Tiny
RICKEDLIN
  • 1994 DODGE RAM

1994 Dodge Ram V8 two wheel drive automatic 180, 00 miles.

Auto shut down, how dose it work? Can you reset it? Cannot get the new fuel pump to work.

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Monday, May 29th, 2017 AT 9:07 PM (Merged)
Tiny
RASMATAZ
  • MEMBER

Check and test the fuel pump relay if okay then test or replace the ASD relay. Could also be the computer controlled of the ASD relay.

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Monday, May 29th, 2017 AT 9:07 PM (Merged)

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